Even though an air quality related health advisory has expired for about half of Wisconsin DNR officials are still warning some of you to either reschedule or cut back on strenuous activity this weekend.
The advisory lasted until noon and covered the area south of a line from Rice Lake through Green Bay and north of Madison.
DNR leaders say the problem is from fine particles in the air being trapped close to the ground by stagnant air conditions.
The stuff comes from things like power plant and factory smoke and vehicle exhaust.
Officials say people with heart, or lung disease, asthma and very elderly or young people should get in touch with a doctor if they experience breathing troubles or chest pain.